Abstract: The technology for x-ray computed tomography(CT) has experienced tremendous growth in recent years.Since the introduction of 4-slice helical scanners in 1998,rapid improvement has been made on CT scanners in terms of the volume coverage,spatial resolution,scan speed,and the number of slices.These advancements not only significantly impact clinical applications,but also bring huge challenges to the CT system design.Because of the complexity of the volumetric CT(VCT) system,various strategies have to be utilized in the design process.These methodologies include theoretical analysis,computer simulation for system performance prediction,bench-top experiments for analysis confirmation,automated image analysis tools for automatically evaluating image performance,and double-blind tests with human observers for parameter optimization.In this paper,we present some of the system design considerations and optimization processes for a 64-slice scanner.These design processes ensure the optimal performance of the cone beam CT scanner.Initial clinical feedback has demonstrated the effectiveness of our approach.